A strong, credible body of scientific evidence shows that climate change is occurring, is caused largely by human activities, and poses significant risks for a broad range of human and natural systems.

The Earth’s climate has changed. The global average surface temperature has increased over the last century and many other associated changes have been observed. The available evidence implies that greenhouse gas emissions from human activities are the main cause. It is expected that, if greenhouse gas emissions continue at business-as-usual rates, global temperatures will further increase significantly over the coming century and beyond.

Ambler doesn’t (here, at least) address the Australian statement, or any of the other statements issued by other national science academies and other scientific organisations around the world. We’ll set that aside for now.

His point appears to be that the Panel on Advancing the Science of Climate Change (presumably responsible for the first quote) is stacked with advocates* of anthropogenic global warming (AGW). He goes into great detail about the nefarious activities of various board members, such as being IPCC authors, members of NGOs, members of advisory boards, having links to the United Nations and being either corporate- or government-funded. Scandalous, I know.

However, Ambler’s entire argument rests on the notion that the aforementioned organisations have already somehow been discredited. That may be true in his head, because the IPCC says all the things he doesn’t like to hear. However, there is no objective reason to think that the IPCC is not essentially fulfilling its intended function: the careful, objective assessment of the science behind climate change and its implications. His argument also relies on the assumption from the outset that the AGW consensus does not exist. If consensus is real, then it’s hard to imagine what could be wrong with having such a panel “stacked” with those who’ve poured their energies into addressing the problem.

Ambler’s other complaint is one I’ve heard repeated for other advocates of climate action – that they’re not climate scientists:

I doubt a dissenting voice on “the science” is ever heard in their deliberations. As can be seen, climate scientists are very much in the minority. It seems that a mix of economists, social scientists, engineers, NGO’s and corporations in receipt of government funding, form the main strength of these particular committees.

I doubt a dissenting voice on “the science” would ever be heard no matter how many climate scientists you added (Ambler has tried to argue against the existence of the consensus, but not too successfully.) Nevertheless, at first glance, it might seem common sense that climate change panels ought to be populated entirely by climate scientists, until you realise that climate science only identifies the existence of the problem. Climate science says nothing about the humanitarian, economic, or even environmental effects of climate change, and it certainly does not say what we might do, as a society, to prevent or mitigate them. This is not a problem with climate science – it simply reflects the cross-disciplinary nature of climate change.

Climate change denialism does not appear to recognise the distinction between all these facets. It does not accept, for instance, that someone can be qualified to talk about reducing CO2 emissions unless they can also convincingly explain the data used to establish the effects of CO2 in the first place. To an armchair “sceptic”, these two discussions belong in the same discipline. Except they don’t. There is a very good reason why the Stern and Garnaut Reviews, for instance, were written by economists rather than climate scientists. Modeling economic costs just isn’t part of climate science; the issue transcends disciplines.

In setting out to undermine all work on climate change**, climate denialists become Jacks of all trades and masters of none. They perceive the entire concept of climate change as being the domain of a single discipline (climate science), because they don’t realise the depth of analysis that underlies each part of that picture. Analysing the effects of greenhouse gases on temperature could be a life’s work, for instance. Analysing the effects of temperature increases on agricultural practices is another life’s work, as is modelling the economic costs and benefits of reducing CO2 emissions, and so on. The true experts each spend their time on a relatively small part of the problem, but paying enormous attention to detail. They rely on other experts to fill in the gaps where needed, because no single person can be an expert in everything. Meanwhile, denialists skip lazily across the entire scope of the problem and engage only in shallow commentary and nitpicking. It would be difficult to comprehend just how many different disciplines are crossed when you naïvely believe that you (and/or those you follow) possess the entire range of necessary expertise.

Thus, the many genuine scientific, humanitarian, political and economic debates regarding climate change are, in denialist circles, mashed crudely into just one big issue, adjudicated solely by climate scientists (except for all the ones who write those terrible papers about hockey stick graphs; they don’t count).

Just for fun, let’s examine the scientific credentials of some SPPI contributors, starting with Dennis Ambler himself. Ambler puts his name to 14 of the last 100 articles (at the time of writing), and thus appears to be the most prolific recent contributor to the SPPI collection. However, try as I might, I cannot find any biographical information on the man at all. Even SPPI’s own Personnel page neglects to mention him. There are no details of his history, qualifications, accomplishments, collaborations, involvements with other organisations, or even interests. “Dennis Ambler” might as well be a pseudonym for all I can tell.***

Next in line is Christopher Monckton, named as the author of 10 of the last 100 articles. Fortunately he is mentioned in the Personnel page, as being an expert on virtually everything, despite not possessing any qualifications at all on anything remotely resembling science or economics. It’s worth a read.

Then there’s Ross McKitrick, with 4 out of 100 articles. He’s an economist, which I hope doesn’t put him offside with Ambler.

The remaining articles were contributed by a slew of authors with (I presume) only a tangential relationship to SPPI itself. I won’t discuss them, except to note that the current President of the Czech Republic Václav Klaus is among them. Doubtless he too specialises in climate science. It’s all about expertise, you understand.

* It’s hard to maintain the correct wording here, since it can be a little unwieldy. Nobody advocates climate change – that’s precisely what we don’t advocate.

** Climate denialism, in aggregate form, opposes every facet of the science on climate change – virtually every finding of every paper – which would be quite a remarkable occurrence if we held it to be intellectually honest. Individuals may accept certain parts of the science to varying extents, and often claim that “nobody” seriously disputes those parts (e.g. that the Earth is currently warming), but in reality every single detail is disputed in some corner or other. (The only exceptions to this are the occasional papers written by denialist champions like Steve McIntyre.)

*** To be fair, it would be hypocritical of me to suggest that all this information is a pre-requisite for making public comments. However, I’m just a pseudo-anonymous blogger, while Dennis Ambler is backed by an “Institute”, conferring a facade of expert credibility.

Two years ago (January 2009), Doran and Zimmerman (D&Z) published a paper based on Zimmerman’s masters thesis. Unsurprisingly, they found that the vast majority (97%) of climate scientists think climate change is real and human-induced. This kind of thing really, really irritates climate change denialists, and so we have Dennis Ambler from SPPI launching into a blisteringly woeful attack on the survey.

He sets the tone with this:

[The survey] was roundly de-bunked at the time by several commentators and it would have been forgotten and consigned to its proper place in the dustbin, if it hadn’t been continually

quoted by activists as fact.

If you’re going to claim that a paper has been “roundly debunked”, a little elaboration would not go astray. Some of us might just be curious about just what arguments were put forth, and you’re not giving us much to go on. Also, if we’re going to lend it such credence, I would expect some sort of expertise to be involved in this debunking, not just a vague reference to unspecified “commentators”.

He then bemoans the surveying of experts as a means of assessing scientific opinion:

This is not arcane knowledge for the select priesthood, this is science and we can read scientific papers and apply quality judgements to them, whether we be specialists or not.

No, Ambler, you really can’t. I know this for two reasons:

Those who’ve genuinely tried to read and understand technical papers in a field they don’t work in will know just how much of an uphill battle it can be. There’s unfamiliar jargon, horrendous equations, often enormous amounts of assumed background knowledge, and frequently little attention paid to overall readability. These papers are written for a very narrow audience, and you can’t just plant the flag of egalitarianism and ignore all the hard work that goes into building the necessary expertise.

Even if you were equipped to read and understand technical papers from any discipline, the sheer quantity of them would make the task logistically impossible. They don’t just dribble out one or two at a time every news cycle. There’s countless thousands (possibly millions) of them, and nobody (scientists included) can ever hope to read them all. That’s why we have surveys. Even researchers themselves rely on survey papers, for instance, to make sense of their own fields.

The remainder of Ambler’s article demonstrates his unique inability to “read scientific papers and apply quality judgments”. I say “unique” because D&Z’s paper is actually quite short and accessible. Given a modicum of education and common sense, there really isn’t much of an excuse for not understanding it.

We are also told that only 5% of the original sample responses were climate scientists, so if we pragmatically apply those proportions we end up with just 141 from the US, 9 from Canada and just 6 from 21 countries around the world, hardly a global consensus.

Is there some significance to the 5% figure? The survey was a broad look at the opinions of Earth scientists. Climate scientists just form an important subset of that population, and it’s hardly the fault of the authors or anyone else if the proportion happens to be 5%.

Moreover, Ambler knows he can estimate the number of respondents from each country, but he seems not to understand that the very same mathematical device is the reason you don’t need to ask everyone in the world. So long as you have a representative sample (and consulting a database of Earth scientists, as D&Z did, would seem to be perfectly acceptable), you can generalise your findings. If 97% of your sample believes X, and your sample is representative of a given group (e.g. climate scientists), then you infer that about 97% of the overall group believes X as well. This is the entire basis of surveys. If this statistical logic did not hold, surveys would not exist.

Why so few non-American climate scientists? That’s just a result of the database used by D&Z, coming as it did from the American Geological Institute. There’s no reason to think that American and non-American climate scientists are likely to have any specific, major points of professional disagreement, so this shouldn’t be a problem.

We find that they originally contacted 10,257 scientists, of whom 3,146 responded, less than a 31% response rate. “Impending Planetary Doom” was obviously not uppermost in the minds of over two thirds of their target population.

31% is a very good response rate, in my experience. I would not have raised an eyebrow if it was only 10% (except that the authors would then have been less well-equipped to draw conclusions). It’s silly to start attributing reasons for non-response, because by definition you don’t have the data. It’s certainly very silly to suggest that 7111 scientists don’t care about the issue merely because they failed to fill out a questionnaire on it. Perhaps they were too busy actually working on the problem!

Ambler does us a service by linking to D&Z’s summary paper, but he’s a bit of a cheapskate:

The paper is behind a pay wall but there is a comprehensive summary here.

It’s obvious from reading Ambler’s article that his own investigative skills cannot penetrate this “pay wall”. Despite describing the summary as “comprehensive”, he repeatedly complains about missing details. For example:

There is little detail of how many peer reviewed papers are needed to qualify as a specialist, it could by their definition be just two papers, one of which needs to be on climate change. What a poor example of scientific enquiry this survey really is.

The one-and-a-bit-page summary paper does not, of course, include all the information from the 141-page thesis. The price for an electronic copy of Zimmerman’s thesis is only $US 2, hardly a prohibitive sum. I bought a copy myself just so that I could write this post. Zimmerman provides an extensive explanation of the process of verifying whether survey respondents are, in fact, active publishers on climate science (page 16). However, this kind of nit-picking was never going to undo the rather stark results.

There were supposed to have been nine questions asked, but we are only given sight of two of them.

Again, this is what you get if you only read a summary. For those interested, the full set of nine questions consisted of four opinion-related questions and five demographic questions:

When compared with pre-1800’s levels, do you think that mean global temperatures have generally risen, fallen, or remained relatively constant?

Do you think human activity is a significant contributing factor in changing mean global temperatures?

What do you consider to be the most compelling argument that supports your previous answer?

Please estimate the percentage of your fellow geoscientists who think human activity is a contributing factor to global climate change.

Which percentage of your papers published in peer-reviewed journals in the last 5 years have been on the subject of climate change?

Age

Gender

What is the highest level of education you have attained?

Which category best describes your area of expertise?

Ambler of course takes issue with the first two questions. For question 1:

Has it got warmer since pre-1800 levels? This really depends on the time period referred to. Do they mean the Little Ice Age, when disastrously cold temperatures caused massive loss of life and untold hardship? Of course temperatures are now warmer than that desperate period in climate history. Is that what they would wish to regard as normal?

Climate denialists often have a mild obsession with two proposed fluctuations in global temperature over the last few hundred years. They explain away the current warming trend by saying that we’re merely coming out of a cold period (the Little Ice Age), and that temperatures have been warmer in the past (the Medieval Warm Period), but the evidence for either of these is rather limited. This is related to another pet denialist obsession: the “hockey stick” graph, which shows that the current warm temperatures are unprecedented over at least the last millennium. It is essential denialist lore that the hockey stick has been discredited. In reality, it has numerous independent replications.

For question 2, on whether human activity is a factor:

This is the classic closed question, in that it implies mean global temperatures are being changed and someone must be responsible.

First, respondents are not asked this question if they previously said that temperatures remained relatively constant; so no, the question does not assume temperatures are being changed. It certainly does not assume that “someone must be responsible” – I have no idea how Ambler could have read that into it.

About half-way through his article, Ambler makes his biggest departure from reality, and one that cannot be excused by lack of information. This divergence begins as follows:

Of [the 3146 respondents], only 5% described themselves as climate scientists, numbering 157. The authors reduce that by half by only counting those who they classed as “specialists”.

The authors do no such thing. They categorise their 3146 respondents by field (climatology, geology, etc.) and whether more than 50% of their recent published papers were related to climate science. In the media, the most widely-reported statistics are, appropriately enough, for actively-publishing climatologists. However, this categorisation does not omit anyone, but merely provides more detailed information.

It is disingenuous to now use the “climate scientists” as a new population sample size. The response figure of 3,146 is the figure against which the 75 out of 77 should be compared and in this case we get not 97% but just 2.38%.

Ambler appears not to notice that there are statistics on the complete set of 3146 respondents, not just the 77 who happen to be actively-publishing climate scientists. Ambler’s 2.38% is the proportion of respondents who agree that humanity has an influence on climate and who also happen to be climate specialists. If you think that climate change is real but you’re not a specialist, Ambler is counting you in the total population but not in the “yes” pile (and so by implication in the “no” pile).

That’s dishonesty if ever I’ve seen it. D&Z expressly state in their summary paper that 90% of respondents overall agreed that temperatures have risen, and 82% agreed that humanity was a factor. Ambler expressly ignores these statistics and then tries to reverse engineer them using profoundly broken mathematics.

The original number contacted was 10,157 [sic] and of those, 69% decided they didn’t want any part of it, but they were the original target population. When the figure of 75 believers is set against that number, we get a mere 0.73% of the scientists they contacted who agreed with their loaded questions.

Ambler now wants to count non-respondents in the total as well, making the unsupportable implication that they would have said “no”. This is utter nonsense and is a complete corruption of general survey methodology. You use the data you have – that’s how science works – not by making assumptions about the data you don’t have.